Such a device has become known from U.S. Pat. No. 4,344,144 (corresponding to West German Offenlegungsschrift No. DE-OS 30,16,684). Via a pneumatic part, the prior-art device generates gas flows with predeterminable pressure and flow values which can occur under normal load as well as increased load of the user of the equipment. The operating parameters of the testing device thus generated are transmitted to a head part which has a testing connection, via which the equipment to be tested is operated with the driving gas pressure and volume generated. By simulating the operating parameters, it is possible to test or even monitor a breathing equipment or a gas mask and breathing equipment or even a simple respiratory aid for function capability. Such a device can also be used for developing new gas masks and breathing equipment in order to test the effects of new components or completely new series of equipment on the expected subsequent case of operation. The test results obtained can be recorded and documented by corresponding measuring points in the head part or even in the equipment to be tested itself.
With the increasing refinement of the pneumatic regulating and control units of gas masks and breathing equipment and the increasing requirements imposed in terms of compact design of the equipment and the economical use of respiratory gas that is carried with the equipment, it is necessary to ensure that the smallest possible amount of respiratory gas will be wasted during the operation of gas masks and breathing equipment. Consequently, e.g., pressure-sensitive control components are able to respond to the pressure in the respiratory tract more readily, so that low pressures and weak respiration flows must increasingly be measured during testing, and permissible deviations from the desired value increasingly become smaller. The disturbances that distort the result of the measurement must be further reduced, so that especially dead space volumes, which are filled with compressible gas, are to be avoided, and the flow conditions for the respiratory gas are to be established such that they will not exart any unfavorable effects on the pressure conditions in the lines carrying respiratory gas.